Abstract: The present invention describes the use of a genetically improved Trichoderma reesei strain allowing to limit microbiological contaminations during an industrial process. The genetic strain improvement allows the latter to overexpress an extracellular protein having known antimicrobial properties and compatible with the secretory system of strains of fungi such as Trichoderma reesei. This modified strain can be used to produce the cellulolytic and/or hemicellulolytic enzymes used in a method of producing ethanol from cellulosic or lignocellulosic materials referred to as “second generation” materials.

Abstract: The present invention describes a method of producing alcohol from pretreated lignocellulosic biomass wherein the enzymatic hydrolysis stage is carried out with cellulolytic and/or hemicellulolytic enzymes produced using at least one effluent from another ethanol production process using a sugar plant as the feedstock. This method can be integrated in a method of producing alcohol from cellulosic or lignocellulosic materials, referred to as second-generation method, comprising the following stages: 1) chemical and/or physical pretreatment of a cellulosic or lignocellulosic substrate, 2) enzymatic hydrolysis of the pretreated substrate using cellulolytic and/or hemicellulolytic enzymes, 3) alcoholic fermentation by a suitable alcohol-producing microorganism of the hydrolysate from stage (2) until a fermentation must is obtained, and separation of the alcohol-producing microorganism used in stage (3), separation/purification of the alcohol.